Friction foot attachment

ABSTRACT

A foot attachment includes a hollow body made of high friction material, a leaf spring of bow-shaped configuration positioned within the body and extending in spring biased engagement between internal opposite side wall portions of the body and having a depressable portion thereof extending through an opening in a side wall portion of the body. The spring is additionally employed as a part of a flash light triggering circuit which also includes a center contact. This spring and center contact form the so called hot foot electrical contacts.

United States Patent 1191 Smart 1 FRICTION FOOT ATTACHMENT [75] lnventor: David C. Smart, Westminster, C010.

[73] Assignee: Honeywell Inc., Minneapolis, Minn.

[22] Filed: Sept. 20, 1973 [21] Appl. No: 399,200

[52] [1.8. CI. 403/315; 354/126; 24/224 LS; 403/331; 248/224 [51] Int. Cl A441: 17/00 [58] Field of Search 24/222 SF, 222 R, 230 BC, 24/224 LS, 224 R; 248/224, 225; 339/198 [56] References Cited UNITED STATES PATENTS 2,266,285 12/1941 Stern 24/224 HE 2,831,412 4/1958 Friedman 248/225 2,980,976 4/1961 Coulter 1 t. 248/187 3,159,730 12/1964 Stafiel 339/198 GA 3,621,988 11/1971 Songer 248/224 3,651,546 3/1972 Hartmann 1. 248/224 FOREIGN PATENTS OR APPLICATIONS United Kingdom 24/230 BC June 3, 1975 927,219 5/1963 United Kingdom 339/198 GA 1,317,392 1/1963 France 339/198 GA 1,415,557 10/1968 Germany 339/198 GA 973,541 10/1964 United Kingdom 339/198 GA Primary ExaminerBernard A. Gelak Attorney, Agent, or FirmArthur H. Swanson; Lockwood D. Burton; John Shaw Stevenson [57] ABSTRACT A foot attachment includes a hollow body made of high friction material, a leaf spring of bow-shaped configuration positioned within the body and extending in spring biased engagement between internal opposite side wall portions of the body and having a depressable portion thereof extending through an opening in a side wall portion of the body. The spring is additionally employed as a part of a flash light triggering circuit which also includes a center contact. This spring and center contact form the so called hot foot electrical contacts.

1 Claim, 3 Drawing Figures SHEET PATEMTEU Jun 3 I975 FRICTION FOOT ATTACHMENT CROSS REFERENCE TO RELATED APPLICATION Subject matter shown and described but not claimed herein is shown, described and claimed in a copending application of Dean M. Peterson et al. Ser. No. 399,276 and the present inventor filed on even date herewith.

BACKGROUND OF THE INVENTION I. Field of the Invention The present invention relates to an improved foot attachment of the type generally classified in the United States Patent Office with article support attaching means (class 248-187).

2. Description of the Prior Art Prior art photographic accessories, for example, pho tographic flash lights have heretofore employed foot attachments to slidably mount these accessories on shoe receptacles that are fixedly mounted on cameras and the like to which the accessory is to be attached. Examples of such foot attachments are shown in the A. R. Schnase US. Pat. No. 3,356,325, the Wallace A. Monson Design patent D2l4,2l4 and the Alwin J. Stahel ll Design patent D214,764.

It has heretofore been the practice with prior art devices of the aforementioned type to provide means to lock the foot in a desired non-movable position on shoe receptacles in order, for example, to maintain the direction of light emitted from a flash light supported by the shoe at a fixed angle. Use of locking means was nec essary because too loose a manufacturing tolerance often times exist between the foot and the shoe. The prior art locking means that is employed in the aforementioned A. R. Schnase patent is a rotatable cam, in the Monson patent it is a screw knob and in the Stahel II patent it is a lever.

SUMMARY OF THE INVENTION An object of the present invention is to provide a construction for a foot attachment which when slidably mounted in an associated shoe receptacle will be held in a desired firm, nonmovable, aligned relationship with, for example, the camera to which the receptacle is attached and which will not require the use of locks such as has heretofore been required by the previously mentioned foot attaching devices.

It is another object of the invention to provide a universal foot attachment of the aforementioned type which can be mounted on all camera shoes now in use even though the sides of the foot attachments or its corresponding shoe receptacle exceeds certain desired specified manufacturing tolerances.

It is another object to provide a leaf spring for the foot that will allow a side of the foot to be pressed into good frictional contact with the shoe receptacle when such a foot is mounted thereon.

It is another object to provide a foot attachment that is economical to manufacture and which can be readily slidably mounted on and removed from an associated shoe receptacle.

In accomplishing these and other objects there has been provided, in accordance with the present invention, a foot made of a high frictional material such as polyurethane which is commercially identifiable under the trade name, of TEXIN E902. The foot is formed with an internal cavity therein. A substantially bow shaped leaf spring is positioned to apply forces against Opposite inner walls of the cavity that are adjacent to two opposing mounting side wall portions of the foot. One arcuate portion of this leaf spring is positioned to extend in an opening in one of the side wall portions of the body. As the extending arcuate spring portion is partially pushed into the housing by an associated side portion of a shoe receptacle the spring transfers the compressing force introduced by the aforementioned movement of the shoe receptacle to an opposite inner wall of the cavity that is adjacent an associated side wall of the foot. As the sides of the foot are slidably moved into a mounting position along the sides of the shoe receptacle a squeezing action will take place in the said last mentioned opposite side wall of the foot and this in turn causes remaining portions of this side wall of the foot to thereby be firmly, frictionally retained in physical surface to surface contact against an associated sidewall of the shoe receptacle.

The bow-shaped spring and the high friction nature of the material from which the foot is constructed thus enables an entire side portion 'of the foot to be frictionally engaged with an associated side of a shoe receptacle while the opposite side of the foot is retained against movement on the shoe receptacle due to a compressing force that is introduced into the spring when the foot is mounted on a shoe receptacle. Additonally, the engagement of the bow-spring with the metallic edge of an associated shoe provides one of the electrical contacts for a so-called hot-shoe connector.

BRIEF DESCRIPTION OF THE DRAWINGS A better understanding of the present invention may be had with the following detailed description when read in connection with the accompanying drawings in which:

FIG. 1 shows a plan view of a friction foot attachment including a hollow body and the bow-shaped leaf spring mounted therein:

FIG. 2 shows an exploded view of the foot attachment: and

FIG. 3 is a right end view of FIG. 1 showing how the parts Of the friction foot attachment can be mounted in firm engagement with a shoe receptacle.

DESCRIPTION OF THE PREFERRED EMBODIMENT Detailed Description Referring to FIGS. 1 and 2 in more detail there is shown a foot attachment 10 which is comprised of three major parts, namely, a hollow body or lower casing part 12, a bow-shaped leaf spring 14 and a top casing 16.

The hollow body 12 of the foot 10 has an internal cavity 18 formed by two internal vertical wall surfaces 20, 22, and an internal base surface 24 into which the bow-shaped leaf spring 14 is inserted as shown in solid line form in FIG. I.

The top casing part 16 covers the upper open end of the hollow body 12 of the foot attachment 10. The top casing part 16 may for example, be a casing portion which forms the base or bottom wall of any photographic accessory, such as a photographic flash unit 25. The top casing part 16 has two apertures 26, 28 therethrough that are in alignment with two similar apertures 30, 32 which extend through the top of the hollow body 12. A pair of screws 34, 36 pass through the aligned apertures 26, 28, and are connected in a tight ened position at their lower end with associated apertured portions 30, 32 formed in body 12.

The top casing 16 thus provides a covering for the spring 14 which prevents the spring from moving in an upward direction out of the hollow body 12.

F 108. 2 and 3 shows that each side of the foot attachment is provided with a top portion 38 and a runner 40 on one side and a similar top portion 42 and a runner 44 on its other sidev The top portion 38 is separated from the associated runner 40 by a recessed side wall portion 46. Similarly, the top portion 42 is separated from its associated runner 44 by a recessed side wall portion 48. Each runner 40, 44 extends outwardly of its respective associated side wall portions 46, 48. The runner 40 is shown so constructed that it does not extend as far away from the side surface 46 as the runner 44 extends away from the surface 48. This condition allows the foot to accommodate the various sized shoes that exist due to tolerance variations between manufacturers.

The arcuate portion 54 of the spring 14, which is shown in solid line form in FIG. 1, extends through a hole 56 forming an aperture in the side wall portion 46.

An outer wall portion of the bow-shaped leaf spring 14 is in contact with an inner wall surface 60 of the foot attachment 10.

A conductive tab 63 extends from the leaf spring 14 to which an electrical lead may be soldered. A center spring 64 comprises the other of the electrical contacts for the hot-shoe connection.

The spring 64 is a torsionally wound spring which is in the shape shown in FIGS. 1 & 2. The spring 64 has a coil spring portion 66, a torsion loop portion 68, a first end portion 76, and an opposite end portion 70. The first end portion 76 comprises a tab to which a second electrical lead may be soldered.

The lower surface of the coils of the coil spring portion 66 is supported by a wall 72 that forms the base of a recess 74 in the shoe attachment 10.

The torsion loop portion 68 of the spring 64 is positionally supported by grooves 78 and 80 formed in the upper face of the casing 12 adjacent the top portion 42 of the foot attachment 10. The looped end 76 extends upwardly through a slot 79 in the top casing 16.

The other end portion 70 of the spring 64 is also of a looped shaped configuration and is shown extending downwardly through and out of a slot 82 that is formed in the base of the foot attachment 10.

The foot attachment 10 is mounted in its assembled condition on the bottom of the casing 16 of a photo flash unit 25. the lower surface of the top wall 16 retains the torsion loop portion 68 of the spring 64 in the groove 80.

An opening 84 is formed in the top casing 16 immediately above the coil portion 66 of the spring 64. A standard shutter cord 86 is provided which has a plug-in electrical connection 88 at one end for connection to the well known shutter contact terminals of a camera, not here shown.

A second electric plug 92, which may be of the type known as a miniature phone plug is connected to the other end of the shutter cord 86. An opening 94 is formed in an end wall of the foot attachment 10 in order that the plug 92 may be aligned with the lower portion of the coil spring 66 as shown in FIG. 1.

In FIG. 3 there is shown an attachment foot 10 secured to the lower surface 16 of a device such as an electronic flash unit 25. The assembly is shown in operative position relative to a complementary mounting shoe 50, shown in phantom. The mounting shoe 50 is of conventional construction and may be securely fastened to another structure such as a camera 52. The mounting shoe 50 includes a metallic frame member having the side edges foled to form a pair of re-entrant lips 58 and 61, respectively. The re-entrant lips 58 and 61, respectively engage the runners 40 and 44 of the foot device 10. in that position, the runners 40 and 44 of the foot are frictionally gripped by the lip positions 58 and 61 of the shoe. Further. that portion 54 of the bow spring 14 which protrudes through the opening 56 is pressed inwardly by the edge of the lip 58. That compression of the spring 14 produces a lateral force on the foot 10 of sufficient magnitude to securely hold the foot rigidly to the shoe 50.

As may also be seen in FIG. 3, the looped end portion of the spring 64 protrudes through the slot 82, to engage a metallic portion of the shoe 50. This arrangement allows the foot 10 to be used with a so-called hotshoe connector, one electrical contact being effected by the engagement of the loop 70 of the spring 64 with one of the contact areas of the hot shoe, the other electrical contact being efi'ected through the engagement of the arcuate portion 54 of the spring 14 with the edge of the lip 58 of the shoe.

In order to make the shoe universally usable, that is also operable with a shoe which is not of the hot-shoe type, means have been provided for accommodating a conventional PC connector cord 86. The PC cord has a miniature, two-terminal phone plug 92 at one end and a connector 88 at the other end suitable for connection to the flash synchronization connector of the camera. When the foot 10 and the associated flash unit are to be used with a camera which does not have a hot-shoe connector, the engagement of two electrical contact means, i.e., the loop 70 of the spring 64 and the portion 54 of spring 14, with the metallic portions of a standard shoe would produce a short-circuit of the electrical terminals of the flash unit, rendering the flash unit inoperative. Therefore, with such a camera, the insertion of the miniature phone plug 92 into opening 94 in the face of the shoe body 10 first causes the tip of the plug to lift the coiled portion 66 of the spring 64 toward the body of the flash unit. Such lifting of the coil 66 also causes the loop portion 70 to be retracted into the slot 82, thereby disengaging that electrical contact from the metallic surface of the standard shoe. As the plug 92 is fully seated in the opening 94, electrical contact is made between the tip contact of the plug 92 andthe coiled portion of the spring 64. At the same time, electrical contact is established between the sleeve contact of the plug 92 and a curved end portion 96 of the spring 14.

Thus it may be seen that there has been provided in accordance with present invention, an improved attachment foot for photographic apparatus which may be used with either a conventional shoe or with a socalled hot-shoe, and which features a rigid mechanical coupling without the need for adjustable clamping devices.

The embodiments of the invention in which an exclusive property or privilege is claimed are defined as follows:

1. A foot means of l-shaped configuration for attachment to a mounting shoe of photographic equipment wherein said shoe is of a C-shaped configuration and is manufactured to any one of a number of different tolerances, comprising a hollow body constructed of high friction material, said body having a hollow portion within the vertical portion of said foot means, said hollow portion being formed by two opposite internal walls whose outer surfaces are walls engageable by said shoe, a bow shaped leaf spring retained in a compressed position within said hollow portion of said body to continuously apply a biasing force in an outward direction between and against said two opposite internal side walls of said body, one of said side walls that forms a vertical portion of said l-shaped hollow body having an opening extending therethrough, the other of said side walls being compressible said bow shaped leaf spring having a portion thereof extending through said 6 opening, said portion of said leaf spring being positioned for compression into said body by a first open end of any selected one of said C-shaped shoes as said body is mounted thereon and to thereby effect a transmission of a force through the remaining part of said leaf spring and outward joint movement thereof with the side wall of said body opposite said wall having said opening thereby to effect a squeezing of said lastmentioned side wall into a firmly mounted frictional engagement against a second open end of said selected shoe, whereby firm attachment of said foot means to any selected one of said shoes is effected notwithstanding that said shoes are not within the same manufacturing tolerance.

t i I i 

1. A foot means of I-shaped configuration for attachment to a mounting shoe of photographic equipment wherein said shoe is of a C-shaped configuration and is manufactured to any one of a number of different tolerances, comprising a hollow body constructed of high friction material, said body having a hollow portion within the vertical portion of said foot means, said hollow portion being formed by two opposite internal walls whose outer surfaces are walls engageable by said shoe, a bow shaped leaf spring retained in a compressed position within said hollow portion of said body to continuously apply a biasing force in an outward direction between and against said two opposite internal side walls of said body, one of said side walls that forms a vertical portion of said I-shaped hollow body having an opening extending therethrough, the other of said side walls being compressible said bow shaped leaf spring having a portion thereof extending through said opening, said portion of said leaf spring being positioned for compression into said body by a first open end of any selected one of said C-shaped shoes as said body is mounted thereon and to thereby effect a transmission of a force through the remaining part of said leaf spring and outward joint movement thereof with the side wall of said body opposite said wall having said opening thereby to effect a squeezing of said last-mentioned side wall into a firmly mounted frictional engagement against a second open end of said selected shoe, whereby firm attachment of said foot means to any selected one of said shoes is effected notwithstanding that said shoes are not within the same manufacturing tolerance. 